The present invention concerns a method of improving the quality of mono or stereo sound reproduction.
It also concerns apparatus for carrying out the method.
Various devices are currently used to reproduce sound. They usually comprise two "enclosures" comprising one or more electro-acoustical transducers called "loudspeakers". Each enclosure usually houses three loudspeakers respectively emitting low, medium and high frequencies. The loudspeakers employ various materials or technologies with a view to improving the reproduction of sound. The "timbres" of these loudspeakers are nowadays very close to the original sound but the problem of spatial resolution has not been solved. These loudspeakers do not reproduce the recorded sound faithfully because they emit sound in one direction only which is always perpendicular to the open side of the enclosure and the same as the direction in which the conical diaphragm of the loudspeaker diverges (this single direction corresponds to the emission denoted E.sub.1 hereinafter, see FIG. 1 in particular). These enclosures are cavities closed on five sides and the loudspeakers are always placed facing the open side, in other words the main axis of the conical diaphragm of the loudspeaker is always perpendicular to the open side of the cavity.
Also known are devices using so-called "bass reflex" enclosures which emit sound in two directions, a forward direction corresponding to the direction in which the diaphragm diverges (as in the loudspeaker emitting sound in a single direction) and a rearward direction (corresponding to the emission E.sub.2 hereinafter, see FIG. 1 in particular); however, this rearward emission follows a particular path in the enclosure in order to render it in phase with the forward wave. Whether these prior art devices provide a single emission direction or two emission directions, a sound is never reproduced homogeneously.
An object of the present invention is to reproduce sounds homogeneously and to improve the resolution and in particular the spatial resolution of the sound by creating sound pressure level differences between different sound emission directions.